Positive contact ignition distributor



Dec. 5, 1961 F. w. BOHN 3,012,111

POSITIVE CONTACT IGNITION DISTRIBUTOR Filed May 20, 1960 To GENERATOR H II/111,

INVENTOR I I I BY 1 I I I TTORNEYS 3,012,111 POSITIVE CONTACT IGNITION DISTRIBUTOR Frank W. Bohn, 1825 Ross Ave, Scranton 9, Pa. Filed May 20, 1960, Ser. N 30,557 8 Claims. (Cl. 200-24) This invention relates to timer or distributor.

The object of the invention is to provide an ignition timer or distributor which will develop a hotter spark across the points of the spark plugs than the ignition timers or distributors at present known.

, Another object of the present invention is to provide an ignition timer or distributor which will develop a longer spark across the points of the spark plugs than the ignition timers or distributors in use at the present time. i

A further object of the present invention is to provide an ignition timer or distributor which will facilitate easier starting of the engine in the winter and, of course, in the summer through the production of hotter and longer sparks at the points of the spark plugs.

An, additional object of the present invention is to provide an ignition timer or distributor in which corrosion of the stationary and rotatable contacts is substantially eliminated.

Still other objects, advantages and improvements according to the present invention will become apparent from the following specification, taken in connection with the accompanying drawing, in which:

FIGURE 1 is a side elevational view, partly in section, of an ignition timer and distributor, according to the present invention, also showing the connections to the induction coil and the spark plugs.

FIG. 2 is an under plan view partly in section, taken on the line 2-2 of'FIG. 1 and looking in the direction of the arrows, and showing the arrangement of the stationary contacts.

FIG. 3 is a top plan view of the rotor of the ignition timer or distributor.

Referring now to the drawing in detail, and to FIG. 1 in particular, the reference numeral designates a rotatable shaft, which is generally driven from the cam shaft (not shown) of an internal combustion engine. The rotor of the ignition timer or distributor is made of some hard insulating material such as phenolic condensation product, Bakelite, etc. and has a flat top 16 and a central boss 14. The boss 14 has a bore 13 therethrough, which receives the upper end of the rotatable shaft 10. The latter is cut away along an arcuate sector 11 and a bowed leaf spring 12 is positioned between the wall of the bore 13 and the bottom of the sector. The rotatable contact element 17 is comprised by a strip of conducting metal, which is inlaid in a suitable groove in the top 16 of the rotor 15 and extends from the center to the circumference'of the latter.

A casing is of generally cylindrical shape and is preferably made of metal. This casing has a central boss 18 at its bottom, in which the shaft 10 is journalled in any suitable manner. A fluid seal (not shown) is preferably provided between the shaft 10 and the wall ofthe bore through the central boss 18.

A cap is also of generally cylindrical shape and is preferably made of some suitable insulating material, similarly a phenolic condensation product, such as Bakelite, etc. This cap is of the proper diameter so that its side wall registers with the side wall of the casing 20.

The cap 25 is held onto the casing 20 by at least two catches 23-23, which are mounted by pins 22 on ears 21 on the casing 20 and engage with lugs 24 on the cap.

The top 26 of the cap has an axial boss 27 and a plua positive contact ignition United States Patent Chice 3,0 12,1 1 1 Patented Dec. 5, 1961 rality of rotatably and arcuately spaced bosses 38 thereon, eight (8) of the latter being shown. A boss 28 is formed on the under side of the top 26, in general alignment with the boss 27 on the upper surface and a bore 29 extends through the two bosses. Within this bore 29 a central contact element 30 is slidably mounted. The upper end of the bore 29 is closed by a metal cup 32, which is force fitted therein. A coil spring 61 is positioned between the bottom of the cup 32 and the central contact element 30, biasing the latter into engage ment with the rotatable contact element 17. A cable 35 has an outer fabric sheath and a central conductor 34, the latter being connected at its inner end to a metal disc 33, which is force fitted into the cup 32.

The arrangement of the contacts for the cables leading to the spark plugs (not shown) is illustrated in FIG. 2. While the arrangement here illustrated is that for an eight (8) cylinder engine, it will be understood that the ignition timer and distributor according to the present invention, would be equally adapt-able to four (4), six (6), or eight (8) cylinder engines. It will be noted that the contacts 42 are arranged in four (4) pairs, the first pair being positioned along the horizontal axis of the distributor cap 25; the second pair is spaced radially outwardly from the first pair and positioned along the 45 line through the second and fourth quadrants; the third pair is spaced radially outwardly from the second pair and positioned along the 45 line through the first and third quadrants; and the fourth pair is spaced radially outwardly from the third pair and positioned along the vertical axis of the distributor cap.

The bosses 36 on the under side of the top 26 of the distributor cap are here shown as of flattened elliptical shape, as are the bores 37 through same, and the slidable contacts 42 Within the latter. The generally aligned upper bosses 38 on the top 26 of the distributor cap are as before, cylindrical, as are the bores 39 through same. Cups 40 are force fitted in the bores 39 and coil springs 41 are positioned intermediate the bottoms of the cups 40' and the slidable contacts 42, biasing the latter into engagement with the rotatable contact element 17 and the top of the rotor 16. The slidable contacts 42 are of flattened elliptical cross section to conform to the shape of the bores 37 through the bosses 36 on the under side of the top 26 of the cap.

The cables which lead to the spark plugs (not shown) have outer fabric sheaths 45 and a control conductor 44, the latter being connected at their ends to metal discs 43, which are force fitted in the cups 40'.

The primary circuit of the ignition system is from the positive terminal of a generator (not shown) over the conductor 47 to the low voltage winding of the ignition coil 46; the negative terminal of the generator is grounded. The other side of this circuit is over the condoctor 48 to a lug 49 in the Wall of the timer casing 20. Inside of the casing 20 there are the contacts of the interrupter (not shown), one of which is connected to the lug 49 and the other is grounded. The primary circuit of the ignition coil 46 is alternately closed and opened by the interrupter. This induces a high voltage in the secondary circuit of the ignition coil. This secondary circuit is comprised by a ground connection (not shown), the high voltage winding of the ignition coil and the cable 35.

It will now be apparent that an ignition timer or distributor constructed as herein described and illustrated has several advantages over the similar devices at present in use. The flat top 16 of the rotor 15 and spring biased input contact 30 and adjacent contacts 42 hearing on the contact element 17 carried by the rotor, provide for firm engagement of the contacts with the contact element.

This is important in two aspects. If there should be a gap between either the central contact 30 and the rotatable contact element 17, or between the latter and any one of the contact elements 42, an arc would be developed across the gap. The latter would result in pitting of either the'central contact 30', the rotatable contact element 17 or the contact element 42. Such pitting would result in corrosion through copper oxide being formed over the pitted surface areas, and hence an appreciable increase in the resistance of the secondary ignition circuit. It is also the case that voltage would be required to force the current across the arc, or arcs, developed, thereby diminishing the voltage available across the points of the spark plug. Another advantage of an ignition timer or distributor according to the construction herein described and illustrated, is that, with the contacts 42 in the shape of a flattened ellipse in cross section and the major axis of the ellipse positioned tangent to the underlyingcircles of rotation of the rotor 15, the cont acts are in engagement with the rotatable contact element 17 for a greater length of time, than would be the case with a contact of cylindrical formation and having the same cross-sectional area. A further improvement of an ignition timer or distributor according to the present invention is that, through the radial staggering of the contacts 42, Wear on the rotatable contact element 17 is distributed at spaced arcuate lines of travel over its length, instead of being concentrated in a single arcuate line of travel.

Having now fully described my invention, what I claim as new and useful and desire to secure by Letters Patent of the United States is:

1. An ignition distributor including a rotatable shaft, a disccarried by said shaft and having a fiat top, a contact element positioned radially of said disc, a contact bearing on said disc and contact element along the axis of rotation of the disc, and a plurality of contacts bearing on said disc symmetrically disposed on the opposite sides of the axis of the disc and ranged in progressively decreasing radial distances from the axis of the disc in the direction of rotation of the latter.

2. A11 ignition distributor including a rotatable shaft, a disc carried by said shaft and having a flat top, a contact element positioned radially of said disc, a contact bearing on said disc and contact element along the axis of rotation of same, and a plurality of contacts of flattened elliptical shape bearing on said disc concentrically positioned with respect to the axis of rotation of the latter and having their major axes positioned tangent to the underlying circles of rotation of the disc.

3. An ignition distributor including a rotatable shaft, a disc carried by said shaft and having a flat top, a contact element carried by said disc and positioned radially of same, a contact bearing on said disc and contact element along the axis of rotation of the disc, and a plu rality of contacts bearing on said disc positioned progressively radially inwardly toward the axis of rotation of the disc in the direction of rotation of the latter.

4. An ignition distributor including a rotatable shaft, a disc carried by said shaft and having a fiat top, a contact element carried by said disc and positioned radially of same, a contact bearing on said disc and contact element along the axis of rotation of the disc, and a plurality of contacts bearing on said disc spaced on reference axes at right angles in the plane of the fiat top 'of the disc,

and a plurality of other contacts bearing on said disc spaced on axes at equal angles to the reference axes.

5. An ignition distributor "including a rotatable shaft, a disc carried by said shaft and having a fiat top, a contact element carried by said disc and positioned radially of same, a contact bearing on said disc and contact element along the axis of rotation of the disc, and a plurality of contacts bearing on said disc at varying distances from the axis of rotation of same comprised by a first pair on a first reference axis of the disc, a second pair on a' second reference axis at'right angles to the first reference axis, a third pair on an axis at equal angles to the reference axes, and a fourth pair on another axis at equal angles to the reference axes. V

6. An ignition distributor including a rotatable shaft, a disc carried by said shaft and having a fiat top, a contact element carried by said disc and positioned radially of same, a contact bearing on said disc and contact element along the axis of rotation of the disc, at first pair of contacts bearing on said discpositioned on a 'firs'tlaxis in the plane of the fiat top of the disc and equally spaced on the opposite sides of the axis of rotation of the latter,

- a second pair of contacts bearing'on said disc positioned on a second axis in the plane of the fiat top of the disc at right angles to the first axis and equally spaced on opposite sides of the axis of rotation of the discand radially inwardly of the first pair of contacts, a third pair of contacts bearing on said disc positioned on a third axis in the plane of the fiat top of the disc at 45 with respect to the first and second axes and equally spaced in opposite sides of the axis of rotation of the disc and radially inwardly of the first and second pair of contacts, and a fourth pair of contacts positioned on a fourth axis in the plane of the flat top of the disc at 45 with respect to the first and second axes and equally spaced in opposite sides of the axis of rotation of the disc and radially inwardly of the second pair of contacts and outwardly of the third pair of contacts.

7. An ignition distributor including a rotatable shaft, a disc carried by said shaft and having a flat top, a contact element positioned radially of said disc, a contact bearing on said disc and contact element along the axis of rotation of same, and a plurality of contacts of flattened elliptical shape bearing on said disc radially positioned with respect to the top and angularly spaced withrespect to the axis of rotation of the latter, and having their major axes positioned tangent to the underlying circles of rotation of the disc. i

I 8. An ignition distributor including a rotatable shaft, a disc carried by said shaft and having a fiat top, a'contact element positioned radially of said disc, a contact bearing on said disc and contact element along the axis of rotation of same, and a plurality of contacts of flattened elliptical shapes bearing on said disc along concentric circles of progressively decreasing diameters in the direction of rotation of the disc.

References Cited in the file of this patent UNITED STATES PATENTS 1,525,119 -De Lorme Feb. 3, 1925 1,953,913 Walther Apr. '3, 1934 2,008,546 Findley July 16, 1935 2,886,661 Skelton et al May 12, 1959 FOREIGN PATENTS 371,214 France "1 Jan. 16,. 1907 

